Hi All,
Today one of our teachers tried to make fire extinguishers with round bottom flasks that had a stopper with tubing through it. Inside the flask he had a solution of sodium hydrogen carbonate and a small suspended mini test tube of HCl. When he inverted them the 2 were supposed to mix and send a stream of water and CO[sub]2 [/sub] out through the tubing.
It didn't work. Does anyone have a tried and proved method of demonstrating the principle.
Maybe we just had too weaker solution of NaHCO[sub]3[/sub]
Wendy
Fire Extinguishers
Fire extinguishers
Hi Wendy
I use a 1L bottle, into which I put 100ml of 2M HCl + 400ml of water.
I use a vial, into which I put 8-10g of bicarb soda.
I tie cotton around the top of the vial, leaving long ends. Secure the cotton to the vial with sticky tape.
I then suspend the vial in the bottle, just down from the neck of the bottle, using the cotton strands, held in place by the rubber stopper.
The one hole rubber stopper has a small piece of glass tubing joined to rubber tubing, into which I attach a glass dropper from a 50ml dropper bottle assembly, to use as my hose end.
Then invert - it is best to secure the stopper in place as it can shoot out with the reaction.
Hope this is of some use - it always works for us.
Alice
I use a 1L bottle, into which I put 100ml of 2M HCl + 400ml of water.
I use a vial, into which I put 8-10g of bicarb soda.
I tie cotton around the top of the vial, leaving long ends. Secure the cotton to the vial with sticky tape.
I then suspend the vial in the bottle, just down from the neck of the bottle, using the cotton strands, held in place by the rubber stopper.
The one hole rubber stopper has a small piece of glass tubing joined to rubber tubing, into which I attach a glass dropper from a 50ml dropper bottle assembly, to use as my hose end.
Then invert - it is best to secure the stopper in place as it can shoot out with the reaction.
Hope this is of some use - it always works for us.
Alice
Fire Extinguishers
Greetings,
We use plastic wash bottles (about 300mL capacity) and a third fill them with vinegar. Then using tea bags (the ones with the strings and tags) take out the staple and empty out the tea. Then put about a teaspoonful of bicarb soda in the tea bag and re-staple. Hold the tea bag inside the wash bottle with the tag hanging outside and screw on the wash bottle lid. Then shake well and invert and voila!!! Fizz everywhere!!
If you want a safer experiment, this eliminates the need to use HCl.
We keep a set of wash bottles just for this purpose. Works well for us!
Robyn
We use plastic wash bottles (about 300mL capacity) and a third fill them with vinegar. Then using tea bags (the ones with the strings and tags) take out the staple and empty out the tea. Then put about a teaspoonful of bicarb soda in the tea bag and re-staple. Hold the tea bag inside the wash bottle with the tag hanging outside and screw on the wash bottle lid. Then shake well and invert and voila!!! Fizz everywhere!!
If you want a safer experiment, this eliminates the need to use HCl.
We keep a set of wash bottles just for this purpose. Works well for us!
Robyn
-
fibreweb
- Posts: 620
- Joined: 20 Jul 2006, 10:00
- School: Oxley High School
- Suburb: Tamworth
- State/Location: NSW
Fire Extinguishers
Hi All,
I would just like to thank Alice for her help. I first tried the method she used using a 1L bottle and then modified it for a class set of 10 (using our good Schott Bottles so I was really glad none got broken)
I kept the vials and tubing ready for the same topic next year. I willl just have to remember where I put them !!
Wendy
I would just like to thank Alice for her help. I first tried the method she used using a 1L bottle and then modified it for a class set of 10 (using our good Schott Bottles so I was really glad none got broken)
I kept the vials and tubing ready for the same topic next year. I willl just have to remember where I put them !!
Wendy
